Dominic O’Connell, head of tax at Coutts, said: "The Government is edging closer to their £10,000 target by the end of this parliament and it will not be surprising if there was a further small increase to the personal allowance for the upcoming tax year.

"To fund this, there could be an NI increase for the self-employed, who currently pay less than the employed, that might be justified by the Government on the basis of the introduction of a flat rate state pension. However, as the pension change is not scheduled until 2017, introducing such an NI ‘alignment’ before then could be controversial."

Francesca Lagerberg, head of tax at Grant Thornton, said: "All the political parties are keen to show they have solutions to the economic situation as the next election grows closer.

"The main tension is likely to be around issues such as taxing the wealthy – how far can you go without stalling growth? And how can you stimulate the economy when there is little money to spend?"